Made available in DSpace on 2017-07-10T18:07:56Z (GMT). No. of bitstreams: 1 Alcione Aparecida de Almeida.pdf: 1918947 bytes, checksum: d5a1da74fcba2bfdd180c1594dcd456b (MD5) Previous issue date: 2013-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study was to evaluate the modified Fenton reactions (RFM), through the addition of six complexing organic separately in each reaction, these being: ascorbic acid (AA), citric acid (CA), ethylenediaminetetraacetic acid (EDTA), gluconic acid (AG), oxalic acid (OA) and tartaric acid (TA), the degradation of textile effluent under varying molar ratios between the total organic carbon, [Fe2+], complexing and [H2O2]. In RFM and Fenton reactions (RF) reactor was used consisting of a borosilicate beaker with a maximum volume of 250 mL, in batch, open, without stirring under room temperature in the optimization phase of time aliquots were removed in the effluent times: 0, 3, 6, 9, 12, 15, 18, 21 and 24 h. The procedure consisted of addition of 250 mL of textile effluent to the reactor for RF and RFM, followed by the oxidant and a catalyst for the RF and oxidizing catalyst and complexing to RFM. RF best results in reduction of TOC was obtained in 12 h treatment under initial pH value of 3.0 and a molar ratio [1:0,9:27,5]. Concerning the [COT:Fe2+:H2O2] where noted a reduction of 91.06% of TOC, COD 94.51%, 99.88% and 99.02% of the turbidity of discoloration. The RFM showed the best results with the use of complexing GA at 15 h of treatment under molar ratio [1:1,31:1,12:27,94], its [COT:Fe2+:AG:H2O2] which promoted reduction of 82.30% of TOC, COD 90.53%, 99.27% and 99.19% of the turbidity of discoloration, TA had similar results in reduction of parameters when the effluent subjected to 12 h of treatment in a molar ratio [1:0,76:0,94:32,13]. Concerning the [COT:Fe2+:AT:H2O2] under these conditions was possible to reduce 75.05% TOC, 94.89% COD, 97.84% turbidity and discoloration of 96.75%. However, RF are effective in the treatment of textile effluents, though the RFM presented as a new possibility of the treatment without the necessity of adjusting the initial pH value. / Este estudo teve por objetivo avaliar as reações de Fenton modificadas (RFM), através da adição de seis complexantes orgânicos isoladamente em cada reação, sendo estes: ácido ascórbico (AA), ácido cítrico (AC), ácido etilenodiaminotetracético (EDTA), ácido glucônico (AG), ácido oxálico (AO) e ácido tartárico (AT), na degradação de efluente têxtil, sob variadas relações molares entre o carbono orgânico total, [Fe2+], complexante e o [H2O2]. Nas RFM e reações de Fenton (RF) foi utilizado reator constituído por um béquer de borossilicato com volume máximo de 250 mL, em sistema descontínuo, aberto, sem agitação, sob temperatura ambiente, na fase de otimização do tempo alíquotas do efluente eram retiradas nos tempos: 0, 3, 6, 9, 12, 15, 18, 21 e 24 h. O procedimento consistiu na adição de 250 mL do efluente têxtil ao reator para as RF e RFM, seguido do oxidante e catalisador para as RF e oxidante, catalisador e complexante para as RFM. Nas RF os melhores resultados de redução do COT foi obtido em 12 h de tratamento, sob valor de pH inicial 3,0 e relação molar [1:0,9:27,5] referente ao [COT:Fe2+:H2O2] aonde constatou-se redução de 91,06% do COT, 94,51 da DQO, 99,88 da turbidez e 99,02% de descoloração. As RFM apresentaram os melhores resultados com a utilização do complexante AG em 15 h de tratamento sob relação molar [1:1,31:1,12:27,94], respectivo [COT:Fe2+:AG:H2O2] a qual promoveu a redução de 82,30% do COT, 90,53% da DQO, 99,27% da turbidez e 99,19% de descoloração, o AT apresentou resultados similares de redução dos parâmetros avaliados, quando submetido o efluente a 12 h de tratamento sob relação molar [1:0,76:0,94:32,13] referente ao [COT:Fe2+:AT:H2O2], nestas condições foi possível a redução de 75,05% do COT, 94,89% da DQO, 97,84% da turbidez e descoloração de 96,75%. Contudo, as RF são eficazes no tratamento de efluentes têxteis, entretanto as RFM apresentam-se como uma nova possibilidade de tratamento sem a necessidade de ajuste do valor do pH inicial.

Rheumatoid arthritis (RA) is a chronic inflammatory, autoimmune disease, characterized by peripheral and symmetrical polyarthritis that leads to joint destruction and deformity due to erosion of cartilage and bone. This is a common disease that affects approximately 1% of the world population and is more common in women than men, however, its peak incidence occurs between the fourth and sixth decades of life. Large amounts of reactive oxygen species (ROS) have been identified in the synovial fluid of RA patients, and such large amounts may lead to oxidative damage of hyaluronic acid, lipid, cartilage matrix and DNA. The accumulation of ROS in the cells, also serves as major intracellular signaling molecules that amplify the inflammatory response synovium proliferative. The objective of this study was to evaluate the levels of ischemia-modified albumin (IMA) and also other markers of oxidative stress and inflammation in 16 patients with RA and 20 healthy controls. IMA levels were significantly higher in RA patients than healthy controls (0.495 ± 0.01 vs 0.433 ± 0.02 ABSU, P=0.038). No significant differences were observed for the other markers studied. Thus it was concluded that besides RA being related to inflammation, elevated levels of IMA in RA patients suggest that this pathology promotes increased oxidative stress. / A artrite reumatoide (AR) é uma doença inflamatória crônica, de caráter autoimune, caracterizada por poliartrite periférica e simétrica, que leva à deformidade e destruição das articulações devido à erosão da cartilagem e do osso. Esta é uma doença comum que afeta aproximadamente 1% da população mundial, sendo mais frequente em mulheres do que nos homens, no entanto, seu pico de incidência ocorre entre a quarta e sexta décadas de vida. Grandes quantidades de espécies reativas de oxigênio (EROs) foram identificadas no fluido sinovial de pacientes com AR, e essa grande quantidade pode levar a dano oxidativo ao ácido hialurônico, lipídios, matriz da cartilagem e ao DNA. O acumulo de EROs nas células, também serve como importantes moléculas sinalizadoras intracelulares que amplificam a resposta inflamatória - proliferativa sinovial. Assim, o objetivo deste estudo foi avaliar os níveis de albumina modificada pela isquemia (IMA) e outros marcadores de estresse oxidativo e inflamação em 16 pacientes com AR e 20 controles saudáveis. Os níveis de IMA foram significativamente maiores no grupo de pacientes com AR do que os controles saudáveis (0.495 ± 0.01 vs 0.433 ± 0.02 ABSU, P=0.038). Não foram observadas diferenças significativas para os outros marcadores estudados. Desta forma, foi possível concluir que além da AR estar relacionada com a inflamação, os níveis elevados de IMA em pacientes com AR, sugerem que esta patologia promova o aumento do estresse oxidativo.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / β-Blockers are an important group of prescription drugs; as a consequence of the large and continuous use, they are commonly found in the environment. This study assessed, preliminary, the inherent risk of the β-blockers Atenolol, Metoprolol and Propranolol, mostly used in the University Hospital of Santa Maria (HUSM), and showed that Propranolol has high Risk Quotient (RQ) of 0.56. HPLC-FLD and SPE methodologies were developed and optimized with the aid of experimental design in order to analyze the occurrence of β-blockers in the HUSM sewage system. The average concentration for Atenolol, Metoprolol and Propranolol found for a week sampling were 2.45, 4.67 and 0.70 μg L-1 in the sewage of the Emergence; 0.95, 0.70 and 0.315 μg L-1 in the HUSM main sewage, and 1.26, 1.27 and 0.56 μg L-1 in the water course receptor, respectively, As possible remediation methodologies for the Hospital Wastewater (HWW) were investigated Advanced Oxidation Process (AOPs) such as photo-Fenton, K2FeO4, Ozonation and O3/Fe2+. The operational parameters were optimized by Response Surface Methodology (RSM). Using optimized conditions for photo-Fenton, Atenolol, Metoprolol and Propranolol were totally degraded in 5 min in aqueous solution, and the mineralization achieved 80% after 120 min of treatment. In HWW, the β-blockers were also totally degraded, however, only 26.5% of the organic matter and 38.6% of the aromaticity were removed. The ready biodegradability and toxicity of the photo-Fenton s samples were estimated by official methods, which indicated an increase in the biodegradability and toxicity. This behavior may be correlated to the formation of degradation products (DPs), relatively, more toxic. The DPs were identified with aid of Liquid Chromatography tandem Mass Spectrometry (LC-MSn). Other proposed degradation process was oxidation-coagulation using Fe(VI), which achieved above 90% degradation for Atenolol, Metoprolol and Propranolol in HWW, while only 17% COD and 60% aromaticity removal. In aqueous solution this process led to 71.7%, 24.7% and 96.5% degradation of Atenolol, Metoprolol and Propranolol, respectively. No mineralization was found, indicating the formation of DPs, identified by LC-MSn. The ready biodegradability of the post-process samples was tested and the results showed that the oxidation-coagulation with Fe(VI) increased the biodegradability. The applicability of ozonation was evaluated varying the pH (3-11) for HWW and aqueous solution. More than 95% of the β-blockers were degraded independently of the initial pH, while above 50% of the aromaticity was removed. In aqueous solution the β-blockers were degraded in 10 min treatment and the identification of the DPs were carried out for process pH 5, 7 and 9. Catalytic ozonation (O3/Fe2+) was applied to HWW and a mineralization of 49% was achieved, with 77.9% aromaticity removal. The β-blockers were totally degraded. Therefore, the present study represents a high qualified analytical information contribution concerning the occurrence of β-blockers in HWW. The studied AOPs/Fe(VI) processes demonstrated to be suitable to degrade Atenolol, Metoprolol and Propranolol. Moreover, high removal of organic matter and aromaticity were achieved by appling O3/Fe2+ process. In many aspects, this work can be considered original, in especial, by regarding the application of Ferrate(VI) and Catalytic Ozonation to the degradation of β-blockers in HWW. / Os β-bloqueadores são uma importante classe de fármacos prescritos na terapia de doenças cardiovasculares e como consequência de seu grande e contínuo uso são comumente encontrados no meio ambiente. O presente estudo avaliou preliminarmente o risco inerente dos β-bloqueadores mais usados no Hospital Universitário de Santa Maria (HUSM), Atenolol, Metoprolol e Propranolol, evidenciando que Propranolol apresentou maior risco inerente com Quociente de Risco teórico de 0,56 (risco médio). Métodos HPLC-FLD e de clean-up/pré-concentração por SPE foram desenvolvidos e otimizados com auxílio de Metodologia de Superfície de Resposta (RSM) para avaliar a ocorrência de β-bloqueadores no sistema de esgotos do HUSM. A concentração ambiental mensurada para Atenolol, Metoprolol e Propranolol durante um ciclo semanal no ponto de lançamento Efluente PA foi 2,45; 4,67 e 0,70 μg L-1, no ponto HUSM principal 0,95; 0,70 e 0,32 μg L-1 e para o Córrego onde os efluentes são lançados de 1,26; 1,27 e 0,56 μg L-1, respectivamente. Como metodologia de remediação da contaminação de β-bloqueadores em Efluente Hospitalar (EH) foram investigados os Processos Avançados de Oxidação (PAOs) Foto-Fenton, K2FeO4, Ozonização e O3/Fe2+. Os parâmetros operacionais foram otimizados por RSM. Usando as condições otimizadas para o processo Foto-Fenton, Atenolol, Metoprolol e Propranolol foram totalmente degradados em 120 min de tratamento, contudo somente 26,5 e 38,6% da carga orgânica e aromaticidade, respectivamente, foram removidos em EH. A pronta biodegradabilidade e toxicidade para amostras aquosas do processo Foto-Fenton foram analisadas por métodos oficiais e indicaram aumento na biodegradabilidade e toxicidade. Este comportamento esta relacionado à formação de Produtos de Degradação (PD) relativamente mais tóxicos. Os PDs foram identificados por Cromatografia Líquida acoplada a Espectrometria de Massas (LC-MSn). Outro processo proposto foi oxidação-coagulação com Fe(VI) que alcançou degradação de Atenolol, Metoprolol e Propranolol acima de 90% em EH, enquanto apenas 17 e 60% da matéria orgânica e aromaticidade foram removidos, respectivamente. Em solução aquosa este processo conduziu a degradação de 71,7; 24,7 e 96,5% de Atenolol, Metoprolol e Propranolol, respectivamente. Nenhuma mineralização foi encontrada indicando a formação de PDs, identificados por LC-MSn. A pronta biodegradabilidade para as amostras aquosas pós-processo foram avaliadas e os resultados encontrados mostraram que houve aumento na biodegradabilidade. A aplicabilidade de ozonização foi avaliada variando o pH de 3-11 em EH e solução aquosa. Mais de 95% dos β-bloqueadores foram degradados independente do pH inicial, enquanto mais de 50% da aromaticidade e 30% da matéria orgânica foram. Em solução aquosa todos os β-bloqueadores foram degradados em menos de 10 min e para os processos em pH 5, 7 e 9 foram identificados os PDs. O processo de O3/Fe2+ alcançou 49% de remoção de matéria orgânica, 77,9% de redução da aromaticidade e completa degradação de Atenolol, Metoprolol e Propranolol em EH. Portanto, o presente estudo contribui com informação analítica qualificada sobre a ocorrência de β-bloqueadores em EH. Os processos de degradação estudados mostraram-se adequados para a degradação de Atenolol, Metoprolol e Propranolol. Ademais, a maior remoção de matéria orgânica e aromaticidade foram observadas para o processo de O3/Fe2+. Em muitos aspectos, este trabalho pode ser considerado original, em especial sobre a aplicação de ferrato(VI) e ozonização catalítica para a degradação de β-bloqueadores em EH.

Les processus d'oxydation avancés à base du radical sulfate (SO4•- -) ont prouvé leur efficacité pour l'élimination de nombreux contaminants. Dans ce travail de thèse, nous avons étudié les processus d'oxydation et de dégradation par le radical sulfate activé à partir du persulfate (PS) pour les molécules suivantes : le diatrizoate, molécule utilisée comme produit de contraste radiologique iodé (DTZ), le salbutamol (SAL) et la terbutaline (TBL), agonistes des récepteurs ß2-adrénergiques. En outre, la réactivité de SO4•- avec la matière organique naturelle (NOM) a également été déterminée. Plus précisément, pour déterminer la réactivité de SO4•- avec NOM, une technique de photolyse laser couplée à la spectroscopie (LFP) a été appliquée pour étudier l'évolution de SO4 • ainsi que la formation d'espèces transitoires à partir de la matière organique. Des constantes de vitesses comprises entre 1530 et 3500 s-1 mgC-1 L ont été obtenues par analyse numérique des équations différentielles et des valeurs moyennes de coefficient d'absorption molaires comprises entre 400 et 800 M-1 cm-1 ont été déterminées pour les espèces transitoires générées de la matière organique.Dans le processus de décomposition de DTZ par PS activé par UV, les principales voies d'oxydation sont la dé-iodination-hydroxylation, la dé-carboxylation-hydroxylation et le clivage de la chaîne latérale. Les résultats ont également indiqué que la vitesse de dégradation du DTZ augmentait avec l'augmentation de la concentration en PS. La présence de NOM a inhibé la dégradation de DTZ, tandis que le bicarbonate l'a amélioré. Pour les ions chlorure un effet négatif a été observé pour des concentrations supérieures à 500 mM.Pour la dégradation du SAL et du TBL, il a été montré que les radicaux phénoxy jouaient un rôle majeur en début de réaction. Par ailleurs, le chlorure n'a pas eu d'effet tangible sur l'efficacité d'oxydation de la SAL et du TBL, tandis que les ions bromures, bicarbonates et le NOM présentaient des effets inhibiteurs / Sulfate radical (SO4•-) based advanced oxidation processes (AOPs) has been proved to be effective for the removal of many contaminants. In this thesis, we investigated the oxidation processes of iodinated X-ray contrast media diatrizoate (DTZ), ß2-adrenoceptor agonists salbutamol (SAL) and terbutaline (TBL) by reaction with SO4•- generated from the activation of persulfate (PS); in addition, the reactivity of SO4•- with natural organic matter (NOM) was also estimated.Specifically, to determine the reactivity of SO4•- with NOM, laser flash photolysis (LFP) technique was applied to monitor the SO4•- decay and the formation of the transients from organic matters. Reaction rate constants comprised between 1530 and 3500 s-1 mgC-1 L were obtained by numerical analysis of differential equations and the weighted average of the extinction coefficient of the generated organic matters radicals between 400 and 800 M-1 cm-1.In the decomposition process of DTZ by UV-activated PS, major oxidation pathways include deiodination-hydroxylation, decarboxylation- hydroxylation and side chain cleavage. Results also indicated that DTZ degradation rate increased with increasing PS concentration. The presence of NOM inhibited DTZ removal rate, while, bicarbonate enhanced it, and chloride ions induced a negative effect above 500 mM. For the degradation of SAL and TBL, phenoxyl radicals were proven to play a very important role from the initial step. Chloride exhibited no effect on the oxidation efficiencies of SAL and TBL, while bromide, bicarbonate and NOM all showed inhibitory effects

Les effluents industriels sont constitués de molécules de natures très diverses, plus ou moins réfractaires aux classiques traitements biologiques. Les normes de rejets évoluant régulièrement vers des contraintes de plus en plus sévères, il semble aujourd'hui nécessaire de proposer des solutions complémentaires pour atteindre de hauts rendements d'épuration. Le premier procédé mis en oeuvre dans ce travail est l'adsorption sur charbon actif. Le caractère novateur de cette technique se situe dans l'utilisation de charbons actifs fabriqués à partir de boues de stations d'épuration d'eaux usées. La seconde méthode est un procédé hybride innovant combinant adsorption et photocatalyse avec TiO2. Les eaux industrielles ciblées sont les effluents colorés, représentés par la tartrazine, et les effluents phénolés représentés par le phénol, l'acide p-hydroxybenzoïque, le p-chlorophénol er le p-nitrophénol. Pour traiter par adsorption les eaux chargées en phénols, plusieurs charbons actifs commerciaux et six charbons de boues ont été utilisés. Il ressort de cette première étude que, malgré leurs faibles surfaces spécifiques, certains charbons de boues présentent des performances très satisfaisantes. Le procédé séquentiel combinant adsorption et photocatalyse a été réalisé avec plusieurs matériaux: un tissu Ahlstrom contenant du charbon et du TiO2, un charbon actif avec dépôt de TiO2 par MOCVD puis un mélange de charbon actif et TiO2 en poudre. Des résultats prometteurs ont été obtenus pour dégrader la tartrazine, en particulier avec le TiO2 déposé sur charbon actif montrant que la proximité de sites d'adsorption et photocatalytique améliore les performances de l'oxydation / In order to explore a new sequential process for water treatment its two steps, adsorption on activated carbon and in situ photocatalytic oxidative regeneration, were investigated successively. Several commercial activated carbons (AC) and sewage sludge based activated carbons (SBAC) were tested with several phenols and one dye as pollutants. Despite low BET surface SBAC exhibits convenient adsorption properties. Photocatalysis on TiO2 was carried out with several materials to achieve activated carbon adsorption- egeneration process: a multilayer tissue with fixed granular AC and TiO2 on a sheet, a composite with TiO2, CVD deposited on AC, and AC-TiO2 powder mixture for comparison. Promising results were obtained especially with TiO2 deposited on AC proving the vicinity of adsorption and photocatalytic sites to be beneficial

Ce travail étudie la faisabilité de différents procédés d’oxydation avancée (POAs) pour le traitement d’eaux usées industrielles. Le secteur visé est l’industrie pharmaceutique, les essais ont été menés sur des eaux synthétiques contenant deux molécules modèles: le paracétamol et la ciprofloxacine. Les procédés étudiés dans ce travail sont l’ozonation, la sonochimie, le traitement par radiation gamma et la dégradation par radiation ultraviolet. Ces techniques sont envisagées en mono-traitement ou en combinaison avec des oxydants et/ou des catalyseurs (peroxyde d’hydrogène, réactif de Fenton et zéolite Fe/MFI). Pour chaque procédé, l'influence de différents paramètres opératoires est analysée et interprétée dans l'objectif de déterminer les meilleures conditions pour la conversion et la minéralisation du chaque polluant. Parmi les paramètres étudiés se trouvent le pH, la concentration en oxydant, la concentration du catalyseur, la dose de la radiation gamma, la fréquence et la puissance ultrasonore. Des effets synergiques importants sont trouvés pour l’ozonation catalytique et pour le photo-Fenton par rapport aux procédés seuls. D’un point de vue purement énergétique, les traitements les plus efficaces sont l’oxydation radio- Fenton et l’oxydation photo-Fenton. Sur la base de ces résultats, un photo-réacteur solaire à recirculation est mis en oeuvre pour traiter par oxydation photo-Fenton des solutions synthétiques préparées avec un mélange de paracétamol et de ciprofloxacine dans l’eau du robinet mais aussi avec des eaux usées réelles dopées avec les deux composés. Dans les deux cas, la dégradation des molécules dépasse 95% dans les 15 premières minutes et la minéralisation dépasse 55% en 180 minutes. / In this work, the feasibility of paracetamol and ciprofloxacin degradation by different advanced oxidation processes (AOPs) was investigated. These molecules are representative of pharmaceutical pollutants found in wastewater. The used processes were the ozonation, the high frequency ultrasound, the gamma radiation and the ultraviolet radiation, alone or in combination with oxidizers and/or catalysts (hydrogen peroxide, Fenton’s reagent and zeolite Fe/MFI). The influence of different operations parameters (pH, oxidant concentration, catalyst concentration, gamma radiation dose and ultrasonic power and frequency) for each processes were studied, in order to determine the optimal operating ranges for the degradation and mineralization of the pharmaceuticals pollutants. Results showed marked synergistic effects by combining individual processes with hydrogen peroxide or Fenton’s reagent, being the most important synergy factors those corresponding to the heterogeneous catalytic ozonation and photo-Fenton processes. Taking into account the energy consumption, the mineralization and the synergy factor, the most effective treatments were radio-Fenton oxidation and photo-Fenton oxidation. Optimal conditions for photo-Fenton oxidation were studied in an open channel reactor at bench scale in tap water and in a real matrix from a municipal wastewater treatment plant. Samples were spiked with a mixture of the pharmaceuticals. In both cases 95% degradation within the first 15 minutes was achieved and its mineralization exceeded 55% in three hours.

M.Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Several industries utilize species of synthetic dyes that are found in their wastewater, which is passed out in the environment. Methylene blue is one of the organic dyes that causes water pollution. It causes damage to the aquatic eco-system and health problems to human beings. It is non-biodegradable due to its chemical nature. Advanced oxidation processes (AOP’s) have been developed for the degradation of these dyes, however, some of these methods are limited due to their high cost and low efficiency. Among these methods, Fenton catalysis has been proven to be an effective method due to its low cost, high efficiency, and re-usability. Iron oxide nanoparticles have been mainly used in Fenton process however they are also limitated due to the forming of secondary pollutants, due to catalysts recovery difficulties, hence they require supporting materials. In this work, iron oxide-based catalyst supported on silica nanofibers were fabricated via electrospinning of silica sol incorporated with iron oxide, using three different routes, (a) Method 1 - wetness incipient impregnation, (b) Method 2 - direct addition of iron precursor to the silica sol and (c) Method 3 - incorporation of iron oxide nanoparticles into silica sol. The effect of iron oxide concentration loadings (1 wt%, 2 wt% and 5 wt %) was studied. Increase in iron content resulted in agglomeration of nanoparticles as embedded in the fibers as evident from their SEM images in method 3.1. The SEM results showed diameters from method 1, 2 and 3 ranging from the distribution ranges of 276 – 288 nm, 243 – 265 nm and 188 nm, respectively. EDS showed the presences of Si, P, Fe, O and P. XRD showed a crystalline phase of magnetite (9 nm) and goethite (32 nm) method 1 and 3, with vibrational modes at 3300 cm-1, 1100 cm-1, 950 cm-1 and 580 cm-1 ascribed to O-H, Si-O-Si, Si-O and Fe-O on the FTIR spectra, it showed both the presence of silica and iron oxide. The degradation of methylene blue was monitored by UV-Vis spectroscopy, the Fenton catalytic activity of the iron-oxide supported on silica nanofibers showed higher catalytic activity compared to the unsupported iron-oxide nanoparticles. The catalyst prepared by wetness incipient impregnation (method 1) had a degradation efficiency of 69.1%, the direct addition of iron precursor to the silica sol (method 2) had 75.2% and incorporation of iron oxide nanoparticles magnetite and goethite with the silica sol had 53.7% and 34.7%, respectively. The catalyst prepared by the direct addition of iron precursor in the sol (method 2) showed a high catalytic activity compared to the other catalyst prepared by other methods. Unsupported Iron oxide nanoparticles had a higher degree of leaching of 1.28 ppm magnetite, and 1.68 ppm goethite, compared to the supported iron oxide in method 1 and method 3. The catalyst incorporated with goethite showed a high degree of leaching, 3.95 ppm and 1.33 ppm. The catalyst with high catalytic activity showed a lower degree of leaching with 0.05 ppm.

This thesis deals with Advanced oxidation processes (AOP) and its aplication for textile wastewaters treatment and reuse. AOP is a modern technology which currently recieves increased attention due to it´s high efficiency in removing resistant and hardly-degradable pollution. Thesis consists of search and practical part. Search part is created by three chapters. First chapter describe briefly wastewater reuse. The second chapter deals with Advanced oxidation processes. AOP principle, AOP division and descriotion is included with the strong focus on the ozonation technology. The third chapter presents the textile industry and its wastewaters. The practical part of this thesis consists of two chapters. Chapter 5 describes testing of textile wastewaters decoloration by ozonation in the selected textile copany and its results. This results are used in chapter 6. Chapter 6 is the study of textile industry treatment and reuse in the selected textile company. This study contains the design of two options for wastewater treatment and reuse in the textile processes.

[ES] La presente Tesis Doctoral se centra en el estudio del comportamiento electroquímico de nuevos electrodos cerámicos basados en SnO2 dopado con Sb2O3. El estudio está orientado a la posterior aplicación de estos electrodos en procesos electroquímicos de oxidación avanzada. Inicialmente, se consideraron diferentes temperaturas de sinterización (entre 1050°C y 1250°C) y se observó que un aumento en la temperatura de sinterización favorecía la deposición del Sb2O3 en la superficie anódica, disminuyendo así la resistividad del electrodo. Posteriormente, se estudió el comportamiento electroquímico de estos nuevos electrodos obteniendo el potencial de descarga del oxígeno mediante la técnica de voltametría de barrido lineal. Los resultados obtenidos revelaron que el valor del potencial de descarga del oxígeno disminuye con el aumento de la temperatura de sinterización. Además, estos electrodos presentaron un comportamiento intermedio entre el ánodo de Pt y el ánodo de BDD. Este último electrodo se emplea habitualmente en los procesos electroquímicos de oxidación avanzada debido a su elevada capacidad para generar radicales hidroxilo, los cuales son capaces de oxidar los compuestos orgánicos a dióxido de carbono y agua. A continuación, se llevaron a cabo ensayos de oxidación electroquímica con estos electrodos cerámicos para seleccionar la temperatura de sinterización. Los resultados mostraron que con el electrodo cerámico sinterizado a 1250°C se alcanza una menor degradación del compuesto orgánico, mientras que los electrodos sinterizados a menores temperaturas presentan un comportamiento similar entre ellos. Por tanto, se seleccionó el electrodo cerámico sinterizado a 1200°C ya que presenta una baja resistividad y un buen comportamiento electroquímico para ser utilizado como ánodo en los procesos electroquímicos de oxidación avanzada. Seguidamente se analizó la vida útil de estos electrodos cerámicos, y se comprobó que la matriz cerámica incrementa en gran medida la estabilidad a la polarización anódica de los electrodos basados en SnO2. Posteriormente, se llevaron a cabo procesos de electro-oxidación en modo galvanostático de distintos contaminantes difíciles de eliminar por las técnicas convencionales utilizando como ánodo los nuevos electrodos cerámicos y el electrodo de BDD, para así poder comparar los resultados obtenidos. Se observó que, aunque con los electrodos cerámicos se consigue degradar el 100% de los distintos contaminantes, el electrodo de BDD es el más eficiente ya que genera mayor cantidad de especies oxidantes activas en su superficie. Para un mismo electrodo, se observó que un aumento en la densidad de corriente aplicada mejora la velocidad de degradación y mineralización de cada contaminante, mientras que la eficiencia eléctrica disminuye. Por otro lado, se estudió el efecto de la presencia de una membrana de intercambio catiónico entre ánodo y cátodo. Los resultados mostraron que el uso de la membrana beneficia la degradación y la mineralización del contaminante, ya que mejora la cinética de reacción anódica y evita la reducción de las especies oxidantes electrogeneradas. A continuación, se analizó la influencia de la concentración del Na2SO4 como electrolito soporte. En este estudio se observó que un aumento en la concentración del Na2SO4 mejora la mineralización del contaminante para el electrodo de BDD y, por el contrario, empeora para el electrodo cerámico. Esto se debe a la capacidad de cada electrodo para oxidar los sulfatos a persulfatos. Por último, se llevaron a cabo ensayos de ecotoxicidad de las muestras tratadas, y se demostró que, en presencia de membrana, a mayor densidad de corriente y con el electrodo de BDD la toxicidad de la muestra es mayor debido a la mayor presencia en disolución de iones persulfato. Por tanto, con el electrodo cerámico, además de alcanzar un elevado grado de degradación del contamina / [CAT] La present Tesi Doctoral es centra en l'estudi del comportament electroquímic de nous elèctrodes ceràmics basats en SnO2 dopat amb Sb2O3. L'estudi està orientat a la posterior aplicació d'aquests elèctrodes en processos electroquímics d'oxidació avançada. Inicialment, es van considerar diferents temperatures de sinterització (entre 1050°C i 1250°C) i es va observar que un augment en la temperatura de sinterització afavoria la deposició de Sb2O3 en la superfície anòdica, disminuint així la resistivitat de l'elèctrode. Posteriorment, es va estudiar el comportament electroquímic d'aquests nous elèctrodes obtenint el potencial de descàrrega de l'oxigen mitjançant la tècnica de voltametria de passada lineal. Els resultats obtinguts van revelar que el valor del potencial de descàrrega de l'oxigen disminueix amb l'augment de la temperatura de sinterització. A més, aquests elèctrodes ceràmics van presentar un comportament intermedi entre l'ànode de Pt y l'ànode de BDD. Aquest últim elèctrode s'utilitza habitualment en els processos electroquímics d'oxidació avançada a causa de la seua elevada capacitat per a generar radicals hidroxil, els quals són capaços d'oxidar els compostos orgànics a diòxid de carboni i aigua. A continuació, es van dur a terme assajos d'oxidació electroquímica amb aquests elèctrodes ceràmics per a seleccionar la temperatura de sinterització. Els resultats van mostrar que amb l'elèctrode ceràmic sinteritzat a 1250°C s'aconsegueix una menor degradació del compost orgànic, mentre que els elèctrodes sinteritzats a menors temperatures presenten un comportament similar entre ells. Per tant, es va seleccionar l'elèctrode ceràmic sinteritzat a 1200 °C ja que presenta una baixa resistivitat i un bon comportament electroquímic per a ser utilitzat com a ànode en els processos electroquímics d'oxidació avançada. Seguidament, es va analitzar la vida útil d'aquests elèctrodes ceràmics, i es va comprovar que la matriu ceràmica incrementa en gran mesura l'estabilitat a la polarització anòdica dels elèctrodes basats en SnO2. Posteriorment es van dur a terme processos d'electro-oxidació en mode galvanostàtic de diferents contaminants difícils d'eliminar per les tècniques convencionals utilitzant com a ànode els nous elèctrodes ceràmics i l'elèctrode de BDD, per a així poder comparar els resultats obtinguts. Es va observar que, encara que amb els elèctrodes ceràmics s'aconsegueix degradar el 100% dels diferents contaminants, l'elèctrode de BDD és el més eficient ja que genera una major quantitat d'espècies oxidants actives en la seua superfície. Per a un mateix elèctrode, es va observar que un augment en la densitat de corrent aplicada millora la velocitat de degradació i mineralització de cada contaminant, mentre que l'eficiència elèctrica disminueix. D'altra banda, es va estudiar l'efecte de la presència d'una membrana d'intercanvi catiònic entre ànode i càtode. Els resultats van mostrar que l'ús de la membrana beneficia la degradació i la mineralització del contaminant, ja que millora la cinètica de reacció anòdica i evita la reducció de les espècies oxidants electrogenerades. A continuació, es va analitzar la influència de la concentració del Na2SO4 com a electròlit suport. En aquest estudi es va observar que un augment en la concentració del Na2SO4 millora la mineralització del contaminant per a l'elèctrode de BDD i, per contra, empitjora per a l'elèctrode ceràmic. Això es deu a la capacitat de cada elèctrode per a oxidar els sulfats a persulfats. Finalment, es van dur a terme assajos d'ecotoxicitat de les mostres tractades, i es va demostrar que, en presència de membrana, a major densitat de corrent i amb l'elèctrode de BDD la toxicitat de la mostra és major a causa de la major presència en dissolució d'ions persulfat. Per tant, amb l'elèctrode ceràmic, a més d'aconseguir un elevat grau de degradació del con / [EN] The present Doctoral Thesis focuses on the study of the electrochemical behaviour of new ceramic electrodes based on SnO2 doped with Sb2O3. The study is oriented at the subsequent application of these electrodes in electrochemical advanced oxidation processes. Initially, different sintering temperatures were considered (between 1050°C and 1250°C) and it was observed that an increase in the sintering temperature favoured the deposition of Sb2O3 on the anodic surface, thus decreasing the resistivity of the electrode. Later, the electrochemical behaviour of these new electrodes was studied by means of the oxygen discharge potential using the linear sweep voltammetry technique. The results obtained revealed that the value of the oxygen discharge potential decreases with increasing the sintering temperature. Furthermore, these electrodes showed an intermediate behaviour between the Pt anode and the BDD one. This last electrode is commonly used in advanced electrochemical oxidation processes due to its high capacity to generate hydroxyl radicals, which are capable of oxidizing the organic compounds to carbon dioxide and water. Then, electrochemical oxidation tests were carried out with these ceramic electrodes to select the sintering temperature. The results showed that with the ceramic electrode sintered at 1250°C, a lower degradation and mineralization of the organic compound is achieved, while the electrodes sintered at lower temperatures showed a similar behaviour. Therefore, the ceramic electrode sintered at 1200°C was selected as it presents low resistivity good electrochemical behaviour to be used as anode in electrochemical advanced oxidation processes. Next, the service life of these ceramic electrodes was analyzed, and it was found that the ceramic matrix greatly increases the anodic polarization stability of the electrodes based on SnO2. Subsequently, electro-oxidation processes were carried out in galvanostatic mode for different contaminants that are difficult to remove by conventional techniques, using the new ceramic electrodes and the BDD electrode as anodes, in order to compare the results obtained. It was observed that ceramic electrodes can be used as anodes for electrochemical oxidation, since for high current densities it is possible to degrade a 100% of the different contaminants. However, the BDD electrode is the most efficient one since it generates more active oxidant species on its surface. For a given electrode, an increase in the current density improves the degradation and mineralization of each contaminant, while the electrical efficiency decreases. On the other hand, the effect of the presence of a cation-exchange membrane between anode and cathode was studied. The results showed that its use benefits the degradation and mineralization of the contaminants, since it improves the kinetics of the anodic reaction and avoids the reduction of the electrogenated oxidant species. Next, the influence of the concentration of Na2SO4 as supporting electrolyte was analyzed. In this study it was observed that an increase in the Na2SO4 concentration improves the mineralization of the contaminant for the BDD electrode and, on the contrary, worsens for the ceramic electrode. This is due to the ability of each electrode to oxidize sulfates to persulfates. Finally, ecotoxicity tests on the treated samples were carried out, and it was shown that, in the presence of the membrane, at higher current density and with the BDD electrode, the toxicity of the sample is greater due to the higher presence of persulfate ions. Therefore, with the ceramic electrode, in addition to achieving a high degree of contaminant degradation, the treated samples are less toxic than the samples treated with the BDD electrode. / Agradezco al Ministerio de Economía y Competitividad por la financiación recibida mediante los proyectos CTQ2015-65202-C2-1-R y RTI2018-101341-B-C21, y a la cofinanciación con los fondos FEDER, que han permitido llevar a cabo la investigación en la Universitat Politècnica de València para la realización de la presente Tesis. También agradecer a Sergio Mestre Beltrán por proporcionarnos los nuevos electrodos cerámicos en los que se ha basado este trabajo. / Mora Gómez, J. (2020). Eliminación de contaminantes orgánicos emergentes mediante procesos electroquímicos de oxidación avanzada [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/158751

[ES] La alta escasez de agua y el constante incremento en la industrialización ha propiciado el deterioro de las reservas de agua como consecuencia de la excesiva generación y liberación de desechos contaminantes. Actualmente, se han reportado una gran variedad de contaminantes de diferente naturaleza, entre ellos se pueden mencionar los microplásticos (MPs) que han sido detectados en agua potable e incluso en animales para la ingesta humana lo cual puede acarrear graves problemas de salud. Cabe mencionar que uno de los mayores problemas a nivel medioambiental de los MPs radica en su alta estabilidad, ya que los métodos habituales utilizados para la eliminación de contaminantes no ejercen efecto. En este sentido, los Procesos de Oxidación Avanzada (POAs) han surgido como una alternativa a la eliminación de contaminantes de difícil degradación, debido a la generación principalmente de radicales hidroxilo que tienen un elevado potencial de oxidación y son muy poco selectivos. En este trabajo nos hemos centrado en el uso del proceso foto-Fenton, con sales de hierro y peróxido de hidrógeno e utilizando la luz solar como fuente de radiación, para llevar a cabo la degradación de MPs, específicamente la poliamida 6,6 (PA66), a pesar de que este polímero no es propiamente un plástico, la literatura lo considera dentro de ellos debido a su importancia como contaminante. A partir de PA66 obtenida de la industria textil, se evaluó el proceso de degradación con distintas técnicas y métodos analíticos destacando entre ellos la microscopía FESEM y la espectroscopía TF-IR. Se realizaron estudios en simulador solar en condiciones habituales de trabajo de procesos foto-Fenton (5 mg/L de Fe, 10 mg/L de H2O2 y pH = 2.8) y qué efectos podían producir tanto el tiempo de radiación como la presencia de una matriz natural como la salinidad en las aguas de tratamiento. Además, se realizaron estudios para confirmar que el proceso de degradación de la PA66 observado (numerosas imperfecciones aparecieron en la superficie del microplástico) era debido a la acción tanto del radical hidroxilo como del radical superóxido utilizando secuestrantes de ambos y comparando los procesos. Posteriormente se evaluó la degradación de la PA66 a nivel planta piloto utilizando dos diferentes fuentes de irradiación: LED vis y LED vis + solar realizando para ello, un estudio previo de diseño de experimentos tipo Doehlert para minimizar recursos y residuos y obtener las óptimas condiciones de tratamiento de la PA66 y, con base a estas condiciones se comparó la degradación de 4 diferentes MPs: PA66, poliamida 6 (PA6), aramida y poliéster (PES). Por último, se estudió la degradación de la PA66 bajo estas mismas condiciones en un periodo de 100 h. Los estudios de estabilidad mostraron que la PA66 no presenta fotólisis ni hidrólisis y los ensayos de degradación mediante el proceso foto-Fenton en un periodo de 7 h mostraron la formación de defectos sobre la superficie de la PA66 y disminución de grupos funcionales de acuerdo microscopia FESEM y FTIR, asimismo, el MP mostró cambios en su punto de fusión a diferentes tiempos de tratamiento como consecuencia de la rotura de las cadenas del polímero. Este mismo efecto se observó en un tiempo de degradación de 100 h de la PA66 con un aumento en el número y diámetro de defectos formados. La adición de NaCl a 30 g/L (alta salinidad) provocó una disminución en el daño generado debido a la reacción de los radicales hidroxilo y formación de especies reactivas con menor potencial de oxidación. La adición de 2-propanol y p-benzoquinona como atrapadores del radical hidroxilo y anión superóxido corroboraron esta suposición. La PA66 tratada en planta piloto mediante el uso de radiación LED vis + solar presentó un mayor grado de degradación en comparación con la tratada únicamente con radiación LED vis (incremento de 90 veces más el área superficial especifica de la PA66 tratada con respecto a la PA66 sin tratamiento). / [CA] L'alta escassetat d'aigua i el constant increment en la industrialització ha propiciat la deterioració dels cossos d'aigua a conseqüència de l'excessiva generació i alliberament de deixalles contaminants. Actualment, s'han reportat una gran varietat de contaminants de diferent naturalesa, entre ells es poden esmentar els microplàstics (MPs) que han sigut detectats en aigua potable i fins i tot en animals per a la ingesta humana la qual cosa pot implicar greus problemes de salut. Cal esmentar que un dels majors problemes a nivell mediambiental dels MPs radica en la seua alta estabilitat, ja que els mètodes habituals utilitzats per a l'eliminació de contaminants no exerceixen cap efecte. En aquest sentit, els Processos d'Oxidació Avançada (POAs) han sorgit com una alternativa a l'eliminació de contaminants de difícil degradació, a causa de la generació principalment de radicals hidroxil que tenen un elevat potencial d'oxidació i són molt poc selectius. En aquest treball ens hem centrat en l'ús del procés foto-Fenton, amb sals de ferro i peròxid d'hidrogen e utilitzant la llum solar com a font de radiació, per a dur a terme la degradació de MPs, específicament la poliamida 6,6 (PA66). A partir de PA66 obtinguda de la indústria tèxtil, es va avaluar el procés de degradació amb diferents tècniques i mètodes analítics destacant entre ells la microscòpia FESEM i la espectroscopía FT-IR. Es van realitzar estudis en simulador solar en condicions habituals de treball de processos foto-Fenton (5 mg/L de Fe, 10 mg/L de H2O2 i pH = 2.8) i quins efectes podien produir tant el temps de radiació com la presència d'una matriu natural com la salinitat en les aigües de tractament. A més, es van realitzar estudis per a confirmar que el procés de degradació de la PA66 observat (nombroses imperfeccions van aparèixer en la superfície del microplàstic) era degut a l'acció tant del radical hidroxil com del radical superòxid utilitzant segrestants de tots dos i comparant els processos. Posteriorment es va avaluar la degradació de la PA66 a nivell planta pilot utilitzant dues diferents fonts d'irradiació: LED vis i LED-vis + solar realitzant per a això, un estudi previ de disseny d'experiments tipus Doehlert per a minimitzar recursos i residus i obtindre les òptimes condicions de tractament de la PA66 i, amb base a aquestes condicions es va comparar la degradació de 4 diferents MPs (PA66, PA6, Aramida i PES). Finalment, es va estudiar la degradació de la PA66 sota aquestes mateixes condicions en un període de 100 h. Els estudis d'estabilitat van mostrar que la PA66 no presenta fotòlisis ni hidròlisi i els assajos de degradació mitjançant el procés foto-Fenton en un període de 7 h van mostrar la formació de defectes sobre la superfície de la PA66 i disminució de grups funcionals d'acord microscòpia FESEM i FT-IR, així mateix, el MP va mostrar canvis al punt de fusió a diferents temps de tractament a conseqüència del trencament de les cadenes del polímer. Aquest mateix efecte es va observar en un temps de degradació de 100 h de la PA66 amb un augment en el nombre de defectes formats i diàmetre dels defectes. L'addició de NaCl a 30 g/L (alta salinitat) va provocar una disminució en el mal generat a causa del secuestrament dels radicals hidroxil i formació d'espècies reactives amb menor potencial d'oxidació. L'addició de 2-propanol i p-benzoquinona com atrapadores del radical hidroxil i anió superòxid van corroborar aquesta suposició. La PA66 tractada en planta pilot mitjançant l'ús de radiació LED-vis + solar va presentar un major grau de degradació en comparació amb la tractada únicament amb radiació LED-vis (increment de 90 vegades més l'àrea superficial especifica de la PA66 tractada respecte a la PA66 sense tractament). L'avaluació de la degradació dels 4 MPs va mostrar que el PES i la aramida no són degradables en aquestes condicions i la PA6 va presentar una menor degradació que la PA66. / [EN] The high scarcity of water and the constant increase in industrialization has led to the deterioration of water bodies as a consequence of the excessive generation and release of pollutant wastes. Currently, a great variety of pollutants of different nature have been reported, among them we can mention microplastics (MPs) that have been detected in drinking water and even in animals for human consumption, which can cause serious health problems. It is worth mentioning that one of the biggest environmental problems of MPs lies in their high stability, since the usual methods used for the elimination of contaminants have no effect. In this sense, Advanced Oxidation Processes (AOPs) have emerged as an alternative for the removal of pollutants that are difficult to degrade, mainly due to the generation of hydroxyl radicals that have a high oxidation potential and are not very selective. In this work we have focused on the use of the photo-Fenton process, with iron salts and hydrogen peroxide and using sunlight as a source of radiation, to carry out the degradation of PMs, specifically polyamide 6,6 (PA66), despite that this polymer is not a plastic, literature considers it among them due to its importance as a pollutant. Using PA66 obtained from the textile industry, the degradation process was evaluated with different techniques and analytical methods, among them FESEM microscopy and TF-IR spectroscopy. Studies were carried out in a solar simulator under usual working conditions of photo-Fenton processes (5 mg/L Fe, 10 mg/L H2O2 and pH = 2.8) and it was studied the effect by the radiation time and the presence of a natural matrix such as salinity in the treatment water. In addition, studies were conducted to confirm that the PA66 degradation process observed (numerous imperfections appeared on the surface of the microplastic) was due to the action of both oxygen species (hydroxyl radical and the superoxide radical) by using scavengers of both and comparing the processes. Subsequently, PA66 degradation was evaluated at pilot plant level using two different irradiation sources: LED vis and LED vis + solar, a previous study of Doehlert type design of experiments to minimize resources and waste and obtain the optimal conditions for PA66 treatment and, based on these conditions the degradation of 4 different MPs: PA66, polyamide 6 (PA6), aramid and polyethylene (PES) was compared. Finally, the degradation of PA66 under these same conditions was studied over a period of 100 h. The stability studies showed that PA66 does not present photolysis or hydrolysis and the degradation tests by the photo-Fenton process in a period of 7 h showed the formation of defects on the surface of PA66 and decrease of functional groups according to FESEM and FTIR microscopy, also, the MP showed changes in its melting point at different treatment time as a result of the breaking of the polymer chains. This same effect was observed at a degradation time of 100 h of PA66 with an increase in the number of defects formed and in their diameters. The addition of NaCl at 30 g/L (high salinity) caused a decrease in the damage generated due to the reaction of hydroxyl radicals and formation of reactive species with lower oxidation potential. The addition of 2-propanol and p-benzoquinone as hydroxyl radical and superoxide anion scavengers corroborated this assumption. PA66 treated in pilot plant using LED vis + solar irradiation showed a higher degree of degradation compared to PA66 treated only with LED vis irradiation (90-fold increase in the specific surface area of treated PA66 with respect to untreated PA66). The evaluation of the degradation of the 4 MPs showed that PES and aramid are not degradable under these conditions and PA6 presented a lower degradation than PA66. / Marcelino Pérez, E. (2022). Proceso foto-Fenton como una alternativa en la degradación de microplásticos de poliamida presentes en aguas residuales textiles [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/191335